This might be a stupid question but I'm still trying to find a clear answer in books and I can't find any, or maybe I just don't get it.

Having capacitors in a DC circuit basically means infinite resistance or 0 current, right? then why would we need capacitors in a DC circuit? I know they can story charge from a battery and then release it but the question is, what do we need that for?

In other words, what's the function of a capacitor in a DC circuit?

 

Hello,

Have a look at this thread:
Decoupling or Bypass Capacitors, Why?

Bertus

 

Another use, because they can store charge, is to provide power to a micropower or nanopower circuit. For example, a PIC demo board from Microchip comes with a small supercapacitor to let the user explore this feature.

 

One example is a DC-DC converter, it has a double function, filter and energy storage.

And a capacitor in DC doesn't have infinite resistancie. It's called isolation resistance and it is betwen 1Mohs to 100MOhms, this implies a very low current called leakage current.